More massive algal blooms likely

Increased rains and dry summers aid the problem, report says

May 6, 2013

Written by

Watchdog/enterprise reporter

PORT CLINTON — Two years ago, toxic algal blooms on Lake Erie were so thick that some anglers said their boats slowed down as they drove through mats of green slime.

The algae grew into the Central Basin, farther across the lake than ever reported.

Beaches posted signs warning swimmers that blooms had been spotted and that contact with the algae could be harmful. The algae contains a toxin that can cause gastrointestinal illness, liver problems and headaches.

It was the worst year on record for the harmful algal blooms, and the condition of Lake Erie that summer renewed national interest in the lake’s health.

Massive blooms like those in 2011 likely will become more frequent, thanks to increased heavy rains and dry summers brought on by climate change, according to a report released last week by the National Wildlife Federation.

Harmful algal blooms have been found on Lake Erie for more than a decade, but researchers are finding a striking relationship between the size of the blooms and large rain events, according to the report “Taken by Storm: How Heavy Rain is Worsening Algal Blooms on Lake Erie.”

Since 1958, there has been a 31-percent increase in the number of days with heavy rains, according to the report.

“We’re going to see more of these large rain events,” said Melinda Koslow, National Wildlife Federation program manager and lead author of the report.

Rainfall has been heavy so far this spring, but it’s too soon to tell whether the lake will have a large bloom this year, Koslow said.

Heavy spring rains wash fertilizer from farmland into the Maumee River, the largest tributary to the Great Lakes, and into other tributaries, like the Sandusky River.

Fertilizer contains phosphorus, which fuels the blooms.

The Lake Erie Basin has the most agricultural land in the Great Lakes region. Agriculture has been identified as a major source of phosphorous, but other sources, including sewer plants, contribute.

The consequences of massive blooms could include fish and bird kills from the animals’ exposure to toxins in the algae, she said. The loss of fish and birds would harm Lake Erie’s $1.5 billion sport fishing industry and its role as a globally important site for migrating birds, she said.

Reducing the amount of phosphorous that flows into Lake Erie would help cut down on the toxic algae. The National Wildlife Federation lists dozens of suggestions for reducing runoff.

Encouraging best management practices for farmers applying fertilizer and restoring wetlands are two of the most important suggestions, Koslow said.

“We really want to see wide implementation of these voluntary practices that are already being done,” she said.

Those management practices include voluntary measures where farmers follow the four R’s: the right fertilizer source at the right rate, right time and right place.

The four R’s discourage farmers from applying fertilizer to frozen ground, where it is more likely to be washed away.

Farmers also can implement other voluntary measures, like planting cover crops and adding buffer strips to prevent runoff.

“If not enough of that is implemented, we’d like to see more regulation and incentives by the government,” Koslow said.

Restoring wetlands also is an important factor because they serve as natural buffers and filters, she said. The Lake Erie watershed has less than 5 percent of the coastal wetlands that existed before the area was settled, according to the report.

“Some of these plants absorb the nutrients, and the water moves on and is much cleaner,” she said.